Hydraulic well pump assemblies



3 Sheets-Sheet 1 BY WW ATTORNEYS March 31, 1964 D. T. HARBISON ETALHYDRAULIC WELL PUMP ASSEMBLIES Filed April 5, 1963 M q 5 N II: 0 W G 4 mu 3 D W. g E A FIG. I

March 1964 D. T. HARBISON ETAL HYDRAULIC WELL. PUMP ASSEMBLIES 5Sheets-Sheet 2 Filed April 5, 1963 F lG.l-0

INVENTORS Dixon T Horbison ATTORNEYS F|G.|-C James A. Burns March 31,1964 D. T. HARBISON ETAL 3,126,329

HYDRAULIC WELL PUMP ASSEMBLIES 3 Sheets-Sheet 3 Filed April 5, 1963INVENTORS Dixon T. Hurbison James A. Burns BY WM ATTORNEYS 3,126,829HYDRAULIC WELL PUMP ASSEMBLIES Dixon T. Hal-bison and James A. Burns,Fort Worth, Tex., assignors to Harbison-Fischer Manufacturing Co., FortWorth, Tex., a corporation of Texas Filed Apr. 5, 1963, Ser. No. 270,9048 Claims. (Cl. 103-46) This invention relates to new and usefulimprovements in hydraulic well pump assemblies.

There have long been in use in both water wells and petroleum wells rodpumps as well as hydraulic pumps, the former utilizing a solid ortubular pump rod or sucker rod extending from ground level to thelocation of the well pump in the well bore and depending uponreciprocation of the pump rods within the well tubing for operation ofthe reciprocal well pump. Such rod pumps have as their primary advantagethe simplicity of the structure involved, but they are subject tobreakages of the pump rods, to wear or damage to the tubing within whichthe rods reciprocate, and in particular to space requirements which lacea severe physical limitation upon the smallness of diameter to which thewell bore may be reduced.

Hydraulic pumps, utilizing a source of motive liquid under pressurepumped downwardly through the well bore to a hydraulically operated pumphave enjoyed some degree of success, but in general either fail tooperate satisfactorily on a fully commercial basis, or become quitecomplex and costly in structure. They are subject to many mechanicaldimculties due to the accumulation of paraffin in the well pumpcomponents, the difiiculty in maintaining the motive or power fluidsufiiciently clean and free of foreign material as to ensure properoperation, and also due to the difficulty of positioning the pump wheredesired in the well bore and in retrieving the pump mechanism forservicing or repair when such becomes necessary. In general, most butnot all of the hydraulic pumps which have been proposed in the past haveproven themselves completely unworkable on a practical basis.

There has also been a growing tendency, particularly in the petroleumindustry, to drill wells of smaller and smaller diameters so that theuse of a conventional rod pump becomes infeasible, while at the sametime, there has not been available a simple yet reliable and durablehydraulic pump for use in such wells. Either the dimensions or thecomplexity of the hydraulic pumps heretofore available preclude the useof such pumps, and in many instances, the initial cost of the hydraulicpumping equipment is not justified in view of the anticipated productionof saleable liquids recovered from the proposed well.

It is, therefore, a primary object of this invention to provide animproved hydraulic well pump assembly which is simple in structure andeconomical to manufacture, install and operate, and which may befabricated with such cross-sectional dimensions as to permit the use ofthe pump assemblies in well bores of relatively small diameter.

A further object of the invention is to provide im- 7 and the relativeduration of the upstroke as compared to the downstroke of the pumpingmechanism varied as may be found suitable.

A still further object of the invention is to provide an improvedhydraulic Well pump assembly in which the liquid produced from the wellformation is maintained completely isolated and kept apart from themotive or power liquid being utilized to drive or operate the hydraulicpump so that the contamination of the latter is avoided.

A still further object of the invention is to provide an improvedhydraulic well pump assembly utilizing to a very large extent,conventional well pump components readily available as standardcommercial items, and requiring the employment of only relatively fewspecialized components.

An additional object of the invention is to provide an improvedhydraulic well pump assembly which is readily and easily mounted in awell bore and correlated with the conductors thereof as well as easilyand quickly removed from the well bore when such becomes desirable.

Other and more particular objects of the invention will be apparent froma reading of the following description.

A construction designed to carry out the invention will be hereinafterdescribed, together with other features of the invention.

The invention will be more readily understood from a reading of thefollowing specification and by reference to the accompanying drawings,wherein an example of the invention is shown, and wherein:

FIG. 1 is a vertical sectional view of the upper end of a hydraulic wellpump assembly constructed in accordance with this invention, and showingthe reversing piston and cylinder thereof,

1G. 1-A is a vertical sectional view, partly in elevation, forming acontinuation of FIG. 1, and showing the means for alternating the flowof motive liquid under pressure,

PIG. l-B is a vertical sectional view forming a continuation of FIG. 1A,and showing the motor cylinder and piston,

FIG. 1-0 is a vertical sectional view, forming a continuation of FIG.1-13, and showing the pump cylinder and piston,

FIG. 1-D is a vertical, sectional view forming a continuation of FIG.l-C, and showing the anchor means for the pump assembly,

FIG. 2 is a schematic view of the well pump assembly showing the same atthe beginning of its downward stroke,

FIG. 3 is a view similar to FIG. 2, showing the well pugnp assembly atthe beginning of its upward stroke, an

FIG. 4 is a fragmentary, vertical, sectional view taken on the line 44of FIG. 1-A.

111 the drawings, the numeral 10 designates a conventional well tubingwhich is shown as being in direct con tact with the earth formation 11at the top of the well, but which in conventional practice would bereceived within the usual well casing which, for purposes ofsimplification, has not been shown, but which itself is normally indirect contact with the earth formation so as to exclude the same fromengagement with the well tubing. A flanged tubing head 12 is mountedupon the upper end of the tubing 10 and has secured thereto the flangedlower end 13 of a reversing cylinder and piston assembly designatedgenerally by the numeral 14.

Thereversing assembly 14 includes an elongate reversing cylinder 15having therein a closed-end, hollow reversing piston 1-6 having a snugsliding fit within the cylinder 15. At the upper end of the reversingassembly there is provided a head member 16' reduced intermediate itsends to form a depending screwthreaded pin 17, and further reduced atits lower end to form a second depending, screwthreaded pin 18 of lessdiameter than the pin 17. A jacket 19 surrounds the reversing cylinder15 and is spaced therefrom to provide an annulus 20, the upper end ofthe jacket '19 being screwthreaded internally and received upon thescrewthreaded pin 17, a conventional O-ring seal 21 being providedbetween the uppermost extremity of the jacket 19 and the upper part ofthe pin 17. The upper end of the reversing cylinder 15 is alsointernally screwthreaded and received upon the pin 18 with an O-ringseal 22 being provided at the upper end of the joint between thereversing cylinder and the pin 18. An axial passage 23 extendsdownwardly through the head member 16 terminating at its lower end in aflared portion 24 which opens into the upper end of the interior of thereversing cylinder 15 above the reversing piston 16.

The reversing cylinder '15 is formed intermediate its ends with aplurality of radially extending ports or passages 25 so positioned thatwhen the reversing piston 16 is in its uppermost position as shown inFIG. 1, the ports 25 are uncovered or exposed to establish communicationbetween the interior of the reversing cylinder 15 below the reversingpiston 16 and the annulus 20'. On the other hand, when the reversingpiston 16 is in its lowermost position within the reversing cylinder 15,as shown in FIG. 3, the ports 25 remain covered by the side walls of thepiston 16 and accordingly, there is no communication between theinterior of the reversing cylinder 15 and the annulus 20.

A cross-over fitting 26 is formed with a depending neck 27 which carriesthe bottom flange 13 for connection to the tubing head 12 and has at itsupper end a reduced, externally screwthreaded pin 28 which receives theinternally screwthreaded lower end of the jacket 19, there again beingprovided an O-ring seal 29 between the lowermost extremity of the jacket19 and the lower portion of the pin 28. At its upper extremity, theupper portion of the cross-over fitting 26 is further reduced to form asecond upstanding pin 30 which receives the lower end of the reversingcylinder 15 in snug sliding engagement, there being provided an O-ringseal 31 between the pin 30 and the lower end of the reversing cylinder15 so that an effective seal is provided but longitudinal spacing of thelower end of the cylinder 15 with respect to the pin 30 is not madecritical.

The cross-over fitting 26 is substantially hollow, having an axial bore32 extending from its lower end to its upper end, the latter beingexposed to the lower portion of the interior of the reversing cylinder15. The member 26 also carries an axial internal conductor 33 closed atits upper end by a plug 34 and having a pair of diametrically opposedbranch passages 35 opening from its interior into the lower end of theannulus 21 below the lower end of the reversing cylinder 15. Further,the conductor 33 is formed with an internal web or bridging member 36above which a lateral passage 37 opens from the interior of theconductor 33 to a discharge conductor 38 extending exteriorly of thecross-over member 26 for the discharge of produced fiuid such as wateror petroleum.

An additional lateral passage 39 extends from the interior of theconductor 33 below the bridging member 36 laterally to the exterior ofthe member 26, and the lowermost portion of the conductor 33 isinternally screwthreaded for reception of the upper end of a motiveliquid conductor 40 extending downwardly and axially through the welltubing 10.

With this arrangement, the interior of the tubing 14) is placed incommunication with the interior of the reversing cylinder 15, theannulus 23 is placed in communication with the discharge conductor 38,and the interior of the motive liquid conductor 41) is placed incommunication with the lateral passageway 39. Also, when the reversingpiston 16 is in its uppermost position, the interior of the d reversingcylinder 15 is placed in communication with the annulus 20 through theports 25.

A conductor block 41 is suitably secured to one outer side of thecross-over fitting 26 and carries a transverse passage 52 registeringwith the lateral passage 39, and an angular passage 43 opening from onelateral wall of the block 4%) to the upper wall or end thereof andreceiving a motive liquid conductor 44 communicating between the passage43 and the axial passage 23 of the head member 16, and thus with theinterior of the reversing cylinder 15 above the reversing piston 16. Afour-way valve 45 is secured to the lateral Wall of the conductor block41 and has an inlet fitting 46 for motive liquid under pressureconnected to the outlet conductor 47 of a hydraulic pump 48 driven by asuitable motor or other means 49 and drawing motive or hydraulic liquidfrom a surge tank 50 for delivery under pressure to the inlet fitting46, there being provided suitable filters and other conventionalelements (not shown) such as pressure gauges and the like,'formaintaining the motive liquid free of foreign matter, ensuring deliverythereof at the desired pressure and carrying out other conventional andusual functions. The four-way valve also has an outlet fitting 47' forre turn of motive or hydraulic liquid to the surge vessel 50 through aconductor 51. Of course, any suitable or desirable means may be employedfor supplying motive liquid under pressure to the inlet fitting 46 andreceiving liquid from the outlet fitting 47. The four-way valve 45 is ofconventional construction and includes an internal, verticallyreciprocal valve plunger or core 52 along with the usual internalpassages 53 which, when the valve core 52 is in its uppermost positionas shown in FIG. 1A place the inlet fitting 46 in communication with aninternal passage 54 of the four-way valve communicating with the passage42, while connecting the passage 43 through an internal passage 55 withthe outlet fitting 47. When the valve core 52 is in its lowermostposition, as shown in FIG. 2, the inlet fitting 46 is placed incommunication with the passage 43, and the outlet fitting 47' is placedin communication with the passage 54. Thus, as the valve core 52 isreciprocated vertically, motive liquid under pressure is alternatelyadmitted to the passage 54 while being exhausted through the passage 55,and then admitted to the passage 55 while being exhausted throughpassage 54. The result is to supply a motive liquid under pressurealternately to the conductor 41) and to the upper end of the reversingcylinder 15 while exhausting such liquid from the other of such members.

For reciprocating the valve core 52 vertically on a controlled basis, asuitable motor or other driving means 56 is provided driving through aspeed controller or speed reduction unit 57, a cam 58 which bearsagainst the usual cam roller 59 on the upper end of the valve core 52.The cam 58 is formed of a pair of cam disks 60 and 61 rotatable withrespect to one another, but normally held in a locked nonrotationalposition by means of a fastening element 62 extending through arcuateslots 63 cut in the cam disks. Each of the cam disks has a lobe 64, andit is obvious that by rotational adjustment of the cam disks withrespect to one another through loosening of the fastening element 62,the combined extent of the lobes 64 may be increased or decreased toincrease or decrease the period of time the valve core 52 is held in itslowermost position, and accordingly to decrease or increase the time thevalve core is held in its uppermost position. Of course, regulation ofthe speed controller 57 permits control and adjustment of the period oftime for which the valve core is held in both its upper and lowerpositions. As shown in FIG. 4, the roller 59 of the valve core is ofsufficient width as to engage the peripheries of both of the'cams 60 and61 at the same time, and accordingly, the angular adjustment of the camdisks becomes effective for simultaneous control of the valve core 52 byboth cam disks.

The pumping section of the assembly includes any suitable or desirabletype of pump anchor 64 having associated therewith a suitable packingmeans 65 for sealing ofi between the interior of the tubing and theusual conductor 66 extending interiorly of the anchor member. Theparticular anchor illustrated in FIG. 1-D of the drawings is thatdisclosed in our copending application, Serial No. 257,296, filedFebruary 8, 1963, and reference is made thereto, but any suitable typeor types of packer and anchor may be employed.

The upper end of the conductor 66 is connected through the usual blindcage standing valve 67, having therein a valve seat 68 and a valve ball69 moving downwardly to engage the seat and close the valve, with thelower end of an elongate pump barrel or cylinder 70 extending upwardlythrough the tubing 10. The usual rod guide 71 having lateral dischargepassages 72 for discharging pro duced liquid from within the pump barrelor cylinder 7 t) to the interior of the tubing 10 is connected to theupper end of the pump cylinder 78, and has a pump rod or actuatingmember 53 extending downwardly therethrough. A pump plunger or piston 74has a snug, sliding, reciprocal fit within the pump cylinder 70, beingprovided with the usual downwardly-closing traveling valve 75 at itslower end and a tubular mandrel 76 extending upwardly from the travelingvalve and carrying the pump piston rings 77. The mandrel 76 extendsupwardly from the traveling valve 75 to a top nut 78 having lateraldischarge passages 79 for conveying produced liquid flowing upwardlythrough the traveling valve 75 and the tubular mandrel 76 to theinterior of the pump cylinder 76 above the pump piston. The nut 78 isscrewthreadedly connected to the lower end of the rod 73 so thatreciprocation of the latter results in reciprocation of the pump pistonwithin the pump cylinder.

The pump rod 73 extends upwardly from the rod guide 71 which has anexternally screwthreaded pin 80 on its upper end through an upper,closed rod guide 81 connected to the lower end of a motor cylinder 82disposed within the tubing 18, the rod guide 81 having on its lower endan externally screwthreaded, depending pin 83. A collar 84 connects thelower rod guide '71 and the upper rod guide 81 by screwthreadedengagement with the pins 80 and 83, and confines between the rod guidesa sectional, sealing liner 85 which seals off around the rod 73 and isin sliding engagement therewith. The liner 85 thus seals the interior ofthe motor cylinder 82 from the interiors of the pump cylinder 78 and thetubing 1%).

A motor piston 86 has a snug sliding fit in the motor cylinder 82. Thepiston 86 is formed with a depending internally screwthreaded box 87 onits lower end within which the upper end of the rod 73 is received, andalso has an upwardly extending, internally screwthreaded box 88 on itsupper end receiving the lower end of an elongate tubular conductor 89.An axial passage 90 extends downwardiy in the piston 86 from the box 88and is divided at its lower end into branch passages 91 openingtherefrom through the lower end of the piston 86 on opposite sides ofthe box 87 outwardly of the rod 73 so as to place the conductor 89 andpassage 90 in communication with the interior of the motor cylinder 82below the motor piston 86.

The upper end of the motor cylinder 82 receives an apertured guidemember 92 similar to the rod guide 71 and having laterally openingpassages 93 placing the upper interior portion of the motor cylinder 82in communication with the interior of the tubing around the pumpassembly. The upper end of the guide member 92 is formed with aninternally screwthreaded box 93 with an upstanding annular neck 94surrounding the same, the screwthreaded lower end of a sealing liner 95being received in the box 93'. A coupling collar 96 has a screwthreadedbox 97 formed on its lower end and surrounded by a depending neck 98,the upper end of the sealing liner 95 being received in the box 97 andjoining the box to the guide member 92 and motor cylinder 82.

A spacing sleeve 99 is received externally around the necks 94 and 98,and serves to position the guide member 92 and the coupling collar 96apart a predetermined distance. The sealing liner sealingly andslidingly engages the exterior surface of the conductor 89 so as to sealoff around the conductor 89 below the collar 96. The coupling member 96also carries an upwardly directed, internally screwthreaded box 108 onits upper end, and the lower screwthreaded end of the motive liquidconductor 40 is received therein. The fluid conductor 89 projectingupwardly through the sealing liner 95 is received in sliding engagementby an axial bore 101 extending between the bottom of the upper box andthe top of the lower box 97 of the member 96, and projects upwardly anappreciable distance within the conductor, as shown in FIG. l-B,terminating in an open upper end 102 through which its internal bore isexposed to the interior of the conductor 40.

In the operation of this hydraulic pump, the entire assembly is loweredinto the bore of the tubing 10 upon the conductor 40 to the desiredelevation in the well bore, and the anchor members 64 and packingelement 65 set in the well in the usual manner, the upper end of theconductor 48 being connected, of course, into the lower end of theconductor 33 and the flange 13 of the reversing assembly 14 beingconnected to the tubing head 12. Now, as the motor 56 and pump motor 49are set in operation motive liquid under pressure is supplied throughthe conductor 47 to the inlet fitting 46.

In the position of the reversing assembly shown in FIGS. 1 and 1-A, theunit is just beginning the downstroke of the pump, and as the valve core52 is moved downwardly by the cam 58, the motive liquid under pressureis caused to flow from the inlet fitting 46 to the passage 55 andpassage 43, and through the conductor 44 into the upper end of thereversing cylinder 15. At the same time, the conductor 40 is broughtinto communication with the outlet or exhaust fitting 47.

As soon as the reversing piston 16 has moved downwardly suificiently tocover the ports 25, produced liquids, such as water or petroleum, willbe forced downwardly from the lower portion of the reversing cylinder 15through the bore 32 of the cross-over fitting 26 around the centralconductor 33 and into the annulus between the tubing 16 and the motiveliquid conductor 40. This pressure is communicated downwardly throughthe tubing and through the ports or passages 93 of the upper guidemember 92 onto the upper side of the motor piston 86 to force the latterand the piston rod 73 downwardly within the motor cylinder 82, alsoforcing the pump piston 74 downwardly within the pump cylinder or barrel70. The standing valve 67 will be closed at this time, and accordingly,the liquid below the pump piston will be forced upwardly through thetraveling valve 75, and consequently, there will be no flow of liquid,to speak of, inwardly through the passages 72 of the rod guide 71. Asthe motor piston 86 moves downwardly in the motor cylinder 82, theliquid beneath the piston in the cylinder is driven upwardly through thepassages 91 and the passage 96 into the interior of the conductor 89 andupwardly therethrough into the conductor 48 to flow through the branchpassage 39 and the passages 53 and 54 to the outlet fitting 47' andreturn to the surge tank 56. It is noted that at the lower end of thestroke of the reversing piston 16, the ports 25 remain covered.

Now, as the cam 58 continues its revolution and permits the valve core52 to move upwardly into the position shown in FIG. 1A, the conductor 44is placed in communication with the outlet fitting 47, and motive liquidunder pressure is directed from the inlet fitting 46 to the passage 42and branch passage 39 and thence into the motive liquid conductor 48.The motive liquid under pressure flows downwardly through the conductor46 and into the open upper end 162 of the conductor 89 and downwardlytherethrough through the passage 90 and passages 91 into the spacewithin the motor cylinder 82 beneath the piston 36, thus forcing thepiston 86 upwardly and forcing produced liquid from the interior of thecylinder 32 above the motor piston 86 outwardly through the passages 93into the tubing. At the same time, through the connecting rod 73, thepump piston 74- is drawn upwardly in the pump cylinder 7t), drawingproduced liquid from the well bore upwardly through the standing valve67, and forcing the produced liquid above the traveling valve 75upwardly and outwardly through the ports 72 and upwardly through thetubing lit. The produced liquid flows upwardly through the cross-overfitting 26 into the lower end of the reversing cylinder 15, forcing thereversing piston 15 upwardly therein until the ports 2% are uncovered,after which the produced liquid is forced outwardly through the ports 25into the annulus 2i? and to storage through the branch passages 35, theconductor 33 and the outlet fitting 38. Thus, only a portion of theliquid forced upwardly by the pump piston 74 is utilized for moving thereversing piston 16 to its upper position, the remainder of the strokebeing utilized for flowing produced liquid upwardly through the tubingand outwardly through the outlet fitting 38.

The portion of the motor cylinder 32 above the motor piston 85constitutes essentially a surge chamber into which and out of which thesame volume of liquid flows on each complete pumping cycle, andsimilarly, the same volume of motive liquid flows in and out of themotor cylinder from beneath the motor piston 86. The same volume ofmotive liquid also flows into and out of the upper portion of thereversing cylinder 15 on each complete pumping cycle, but the flow ofproduced liquid through the pumping section of the assembly is alwaysupwardly through the standing valve 67 and the traveling valve 75.Obviously, the pump piston 74 may be given as long a stroke as desired,since all that is necessary is that the reversing cylinder 15 forcesufficient liquid downwardly through the tubing on the downstroke toreturn the pump piston to the lowermost end of its stroke. The volume ofliquid produced by the pump piston 74 on each stroke is in no waydependent upon limited mechanical movements at the ground surface suchas those of the conventional pumping jack and other usual mechanicalpumping equipment utilizing a rod-type pump. At the same time, all theadvantages of a rod-type pump are realized along with the advantages ofa hydraulic pumping system.

It is to be noted that the motive liquid is fully and completelyisolated at all times from the produced liquid, and hence, contaminationof the motive liquid is avoided and maintenance of the motive liquid inclean and optimum condition is achieved. Further, it is pointed out thatall of the sealing elements are required to seal on one face only, andthe difliculties inherent in requiring a sealing element to seal on bothinner and outer faces are avoided.

The foregoing description of the invention is explanatory thereof andvarious changes in the size, shape and materials, as well as in thedetails of the illustrated construction may be made, within the scope ofthe appended claims, without departing from the spirit of the invention.

What we claim and desire to secure by Letters Patent is:

1. A hydraulic well pump assembly including a pump cylinder member, apump plunger member in the pump cylinder member, one of the pump membersbeing adapted to be anchored in a well tubing, downwardly-closing valvemeans in the pump cylinder member, downwardly-closing valve means in thepump plunger member, one of the pump members being reciprocable withrespect to the other, the reciprocable pump member having passage meansfrom its valve means to the exterior of the pump, a motor cylinder aboveand connected to the pump member adapted to be anchored in a welltubing, a motor piston reciprocable in the motor cylinder, first meanssealing the interior of the motor cylinder below the motor piston,reciprocating means connecting the motor piston to the reciprocable pumpmember and extending through the sealing means, a conductor extendingupwardly from the motor cylinder, a tubular stem extending upwardly fromthe motor piston into the conductor and having its interior exposed tothe interior of the motor cylinder below the motor piston, secondsealing means in the conductor receiving the tubular stem in slidingsealing engagement, the conductor having an outlet opening exteriorly ofthe pump between the motor piston and the second sealing means, areversing cylinder adapted to be mounted at the top of a well in whichthe pump cylinder member is disposed, a reversing piston in thereversing cylinder, the reversing cylinder having a produced liquidoutlet intermediate its ends so positioned as to be covered by thereversing piston when the latter is at one end of its stroke in thereversing cylinder and to be exposed to the interior of the reversingcylinder when the reversing piston is at the other end of its stroke inthe reversing cylinder, means exposing one end of the reversing pistonto the exterior of the pump, and means for supplying motive liquid underpressure alternately to the opposite end of the reversing piston and tothe interior of the conductor above the second sealing means.

2. A hydraulic well pump assembly adapted to be associated with a welltubing and a motive fluid conductor in a well bore and including; areversing assembly adapted to be mounted at the top of a well including,a reversing cylinder adapted to have one end connected to a well tubing,a reversing piston reciprocably positioned in the reversing cylinder andhaving one end adapted to be exposed to the interior of the well tubing,the reversing cylinder having a produced liquid outlet intermediate itsends so positioned as to close when the reversing piston is at one endof its stroke in the reversing cylinder and to be exposed to theinterior of the reversing cylinder when the reversing piston is at theopposite end of its stroke in the reversing cylinder, and means forsupplying motive liquid under pressure alternately to the end of thereversing piston opposite that end adapted to be exposed to the interiorof the well tubing and to the interior of the motive fluid conductor;and a well pump including, a motor cylinder adapted to be connected tothe motive fluid conductor, a motor piston reciprocably positioned inthe motor cylinder, a tubular stem extending upwardly from the motorpiston, sealing means sealing between the motor cylinder and the motivefluid conductor and receiving the tubular stem in sliding sealingengagement, the motor cylinder having a liquid flow passage to theinterior of the tubing from between the motor piston and the sealingmeans, the motor piston having a flow passage between the tubular stemand the interior of the motor cylinder below the motor piston, areciprocal well pump below the motor cylinder having a produced fluidoutlet to the well tubing, a movable pumping member forming a part ofthe reciprocal well pump, means for sealing ofi between the exterior ofthe reciprocal pump and the well tubing below the produced fluid outletof the reciprocal pump, and actuating means extending between the motorpiston and the movable pumping member of the reciprocal well pump.

3. A hydraulic well pump assembly adapted to be associated with a Welltubing and a motive fluid conductor in a well bore including; a wellpump including a pump cylinder having its lower end adapted to beexposed to the interior of the well tubing, means for anchoring the pumpcylinder in the well tubing and sealing off the exterior of the pumpcylinder from the well tubing therebelow, a pump piston in the pumpcylinder, the well cylinder having a first liquid outlet extending fromits interior above the pump piston to the interior of the well tubing,downwardly-closing valve means carried by the pump cylinder and the pumppiston, a motor cylinder having its lower end connected to the upper endof the pump cylinder, first sealing means between the motor cylinder andthe pump cylinder above the first liquid outlet, a motor piston in themotor cylinder, actuating means connected between the motor piston andthe pump piston sealingly and slidably engaged by the first sealingmeans, the motor cylinder being adapted to be connected to the motivefluid conductor, second sealing means adjacent the upper end of themotor cylinder for sealing between the motor cylinder and the motivefluid conductor, the motor cylinder having a second liquid outletextending from its interior above the motor piston and below the secondsealing means to the interior of the well tubing, a tubular stemextending upwardly from the motor piston through the second sealingmeans in sealing and sliding engagement with the latter, the motorcylinder having passage means extending from the interior of the tubularstem to the interior of the motor cylinder below the motor piston; and areversing assembly adapted to be mounted at the top of a well including,a reversing cylinder adapted to have one end connected to the upper endof the well tubing, a reversing piston reciprocably positioned in thereversing cylinder and having a first end exposed to the well tubing,and means for alternately supplying motive liquid under pressure to themotive fluid conductor and to the reversing cylinder at that end of thereversing cylinder opposite the end adapted to be connected to the welltubing, the reversing cylinder having a produced liquid outletintermediate its ends positioned to be uncovered by the reversing pistonwhen the latter reaches the end of its stroke toward that end of thereversing cylinder opposite the end of said cylinder adapted to be comnected to the well tubing and to be covered at all other times.

4. A hydraulic well pump assembly as set forth in claim 3 wherein ajacket surrounds the reversing cylinder it? and the produced liquidoutlet opens from the reversing cylinder into the jacket.

5. A hydraulic well pump assembly as set forth in claim 3, and means forvarying the frequency with which the supplying of motive liquid to thereversing cylinder and the motive liquid conductor is alternated.

6. A hydraulic well pump assembly as set forth in claim 3, and means forvarying the relative lengths of time the motive liquid is supplied tothe reversing cylinder and to the motive liquid conductor.

7. A hydraulic well pump assembly as set forth in claim 3 wherein themeans for alternately supplying motive liquid under pressure includes acam-operated fourway valve, an operating cam for the four-way valve, atleast two abutting cam disks forming the cam, a cam lobe on each camdisk, and a releasable fastening holding the cam disks againstrotational movement with respect to one another, releasing of thefastening allowing rotational adjustment of the cam disks with respectto one another to vary the area of the cam lobes exposed to the four-wayvalve.

8. A hydraulic well pump assembly as set forth in claim 3 wherein themeans for alternately supplying motive liquid under pressure includes acam-operated fourway valve, an operating cam for the four-way valve, amotor for driving the cam, and a speed controller connecting the motorto the cam to vary the speed of driving the latter.

References Cited in the file of this patent UNITED STATES PATENTS784,435 Russell Mar. 7, 1905 3,020,848 Green Feb. 13, 1962

1. A HYDRAULIC WELL PUMP ASSEMBLY INCLUDING A PUMP CYLINDER MEMBER, APUMP PLUNGER MEMBER IN THE PUMP CYLINDER MEMBER, ONE OF THE PUMP MEMBERSBEING ADAPTED TO BE ANCHORED IN A WELL TUBING, DOWNWARDLY-CLOSING VALVEMEANS IN THE PUMP CYLINDER MEMBER, DOWNWARDLY-CLOSING VALVE MEANS IN THEPUMP PLUNGER MEMBER, ONE OF THE PUMP MEMBERS BEING RECIPROCABLE WITHRESPECT TO THE OTHER, THE RECIPROCABLE PUMP MEMBER HAVING PASSAGE MEANSFROM ITS VALVE MEANS TO THE EXTERIOR OF THE PUMP, A MOTOR CYLINDER ABOVEAND CONNECTED TO THE PUMP MEMBER ADAPTED TO BE ANCHORED IN A WELLTUBING, A MOTOR PISTON RECIPROCABLE IN THE MOTOR CYLINDER, FIRST MEANSSEALING THE INTERIOR OF THE MOTOR CYLINDER BELOW THE MOTOR PISTON,RECIPROCATING MEANS CONNECTING THE MOTOR PISTON TO THE RECIPROCATINGPUMP MEMBER AND EXTENDING THROUGH THE SEALING MEANS, A CONDUCTOREXTENDING UPWARDLY FROM THE MOTOR CYLINDER, A TUBULAR STEM EXTENDINGUPWARDLY FROM THE MOTOR PISTON INTO THE CONDUCTOR AND HAVING ITSINTERIOR EXPOSED TO THE INTERIOR OF THE MOTOR CYLINDER BELOW THE MOTORPISTON, SECOND SEALING MEANS IN THE CONDUCTOR RECEIVING THE TUBULAR STEMIN SLIDING SEALING ENGAGEMENT, THE CONDUCTOR HAVING AN OUTLET OPENINGEXTERIORLY OF THE PUMP BETWEEN THE MOTOR PISTON AND THE SECOND SEALINGMEANS, A REVERSING CYLINDER ADAPTED TO BE MOUNTED AT THE TOP OF A WELLIN WHICH THE PUMP CYLINDER MEMBER IS DISPOSED, A REVERSING PISTON IN THEREVERSING CYLINDER, THE REVERSING CYLINDER HAVING A PRODUCED LIQUIDOUTLET INTERMEDIATE ITS ENDS SO POSITIONED AS TO BE COVERED BY THEREVERSING PISTON WHEN THE LATTER IS AT ONE END OF ITS STROKE IN THEREVERSING CYLINDER AND TO BE EXPOSED TO THE INTERIOR OF THE REVERSINGCYLINDER WHEN THE REVERSING PISTON IS AT THE OTHER END OF ITS STROKE INTHE REVERSING CYLINDER, MEANS EXPOSING ONE END OF THE REVERSING PISTONTO THE EXTERIOR OF THE PUMP, AND MEANS FOR SUPPLYING MOTIVE LIQUID UNDERPRESSURE ALTERNATELY TO THE OPPOSITE END OF THE REVERSING PISTON AND TOTHE INTERIOR OF THE CONDUCTOR ABOVE THE SECOND SEALING MEANS.